Change ObjCRuntime::LookupClass -> GetClass, and now takes the

Change ObjCRuntime::LookupClass -> GetClass, and now takes the
  ObjCInterfaceDecl.

Change ObjCRuntime::GenerateMessageSendSuper to take the
  ObjCInterfaceDecl for the super class, instead of just its name.

Change EmitObjCMessageExpr to make the right runtime calls for super
  sends in class methods (i.e. a super send with the class object as
  the receiver).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54833 91177308-0d34-0410-b5e6-96231b3b80d8